Develop Reference

XmlElement InnerText property

I'm delving into the world of XmlDocument building and thought I'd try to re-build (at least, in part) the Desktop tree given by Microsoft's program UISpy.
So far I am able to grab a child of the desktop and write that to a XML document, and then grab each child of that and write those to an XML document.
So far the code looks like this...
using System.Windows.Automation;
using System.Xml;
namespace MyTestApplication
{
internal class TestXmlStuff
{
public static void Main(string[] args)
{
XmlDocument xDocument = new XmlDocument();
AutomationElement rootElement = AutomationElement.RootElement;
TreeWalker treeWalker = TreeWalker.ContentViewWalker;
XmlNode rootXmlElement = xDocument.AppendChild(xDocument.CreateElement("Desktop"));
AutomationElement autoElement = rootElement.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, "GitHub"));
string name = autoElement.Current.Name;
while (autoElement != null)
{
string lct = autoElement.Current.LocalizedControlType.Replace(" ", "");
lct = (lct.Equals("") ? "Cusotm" : lct);
XmlElement temp = (XmlElement)rootXmlElement.AppendChild(xDocument.CreateElement(lct));
//temp.InnerText = lct;
string outerXML = temp.OuterXml;
rootXmlElement = temp;
autoElement = treeWalker.GetNextSibling(autoElement);
}
}
}
}
...and the resulting XML file...
Now, when I add a line to change the InnerText Property of each XML element, like temp.InnerText = lct I get an oddly formated XML file.
What I expected from this was that each InnerText would be on the same line as the start and end tags of the XML element, but instead all but the last element's InnerText is located on a new line.
So my question is, why is that? Is there something else I could be doing with my XML elements to have their InnerText appear on the same line?

As I said in a comment, XML isn't a display format, so it gets formatted however IE chooses to do so.
To get closer to what you were expecting, you might want to consider using an attribute rather than innertext:
XmlElement temp = (XmlElement)rootXmlElement.AppendChild(xDocument.CreateElement(lct));
var attr = xDocument.CreateAttribute("type");
attr.Value = lct;
temp.Attributes.Append(attr);
IE displays the attributes within the opening element, which may be good enough for your purposes.
From the XML perspective, what you're currently creating is called Mixed Content - you have an element that contains both text and other elements. From a hierarchical perspective, those text nodes and other elements occupy the same position within the hierarchy - so I'd assume that this is why IE is displaying them as "equals" - both nested under their parent element and at the same indentation level.

Updating a specific XML node

I am new to XML files and how to manage them. This is for a web app I am writing (aspx).
At the present time I am able to find the first instance of a node and add an item to it with the following code:
xmlClone.Element("PCs").Element("PC").Element("pc_hwStatus").AddAfterSelf(new XElement("user_name", txt_v0_nombre.Text));
What I really want is to add ("user_name", txt_v0_nombre.Text) to a node in particular, not the first one. The content of my XML file is:
<PCs>
<PC>
<pc_name>esc01</pc_name>
<pc_ip>10.10.10.10</pc_ip>
<pc_hwStatus>Working</pc_hwStatus>
</PC>
<PC>
<pc_name>esc02</pc_name>
<pc_ip>10.10.10.11</pc_ip>
<pc_hwStatus>Under Maintenance</pc_hwStatus>
</PC>
</PCs>
The decision of what node to update is made selecting an item from a dropdown list (the PC name).
With my current code, the new item is always added as last line of node with "pc_
name = esc01". I want to be able to added it to esc02 or esc03 and so on... How can this be accomplished? (Using xdocument)

If I understand you correctly, what you are looking for is the FirstOrDefault extension method. In there specify which node you are wanting, in this case a string from your dropdown box, which can be passed in. So to get the first node:
var pc = xmlClone.Element("PCs").Elements("PC").FirstOrDefault(e => e.Element("pc_name").Value == "esc01");
Now you have this in your XElement:
<PC>
<pc_name>esc01</pc_name>
<pc_ip>10.10.10.10</pc_ip>
<pc_hwStatus>Working</pc_hwStatus>
</PC>
To get any element like that, just replace this clause:
.FirstOrDefault(e => e.Element("pc_name").Value == "esc01");
with this one
.FirstOrDefault(e => e.Element("pc_name").Value == desiredPC);
where desiredPC is the value of the xml node: pc_name.
Now to add your data just call the plain old Add method:
pc.Add(new XElement("user_name", txt_v0_nombre.Text);
That should do the trick for you.

Here's a solution that uses LINQ query syntax with LINQ to XML:
XDocument document = XDocument.Parse(xmlContent);
string pcName = "esc02";
IEnumerable<XElement> query =
from pc in document.Element("PCs").Elements("PC")
where pc.Element("pc_name").Value.Equals(pcName)
select pc;
XElement xe = query.FirstOrDefault();
if (xe != null)
{
xe.Add(new XElement("user_name", "DMS"));
}
I have incorporated your sample data and this query into a demonstration program. Please see below for the output from the demonstration program followed by the program itself.
Expected Output
<PC>
<pc_name>esc02</pc_name>
<pc_ip>10.10.10.11</pc_ip>
<pc_hwStatus>Under Maintenance</pc_hwStatus>
<user_name>DMS</user_name>
</PC>
Demonstration Program
using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
namespace LinqToXmlDemo
{
public class Program
{
public static void Main(string[] args)
{
string xmlContent = GetXml();
XDocument document = XDocument.Parse(xmlContent);
XElement xe = FindPCName(document, "esc02");
if (xe != null)
{
xe.Add(new XElement("user_name", "DMS"));
Console.WriteLine(xe);
}
else
{
Console.WriteLine("Query returned no results.");
}
}
private static XElement FindPCName(XDocument document, String pcName)
{
IEnumerable<XElement> query =
from pc in document.Element("PCs").Elements("PC")
where pc.Element("pc_name").Value.Equals(pcName)
select pc;
return query.FirstOrDefault();
}
private static String GetXml()
{
return
#"<?xml version='1.0' encoding='utf-8'?>
<PCs>
<PC>
<pc_name>esc01</pc_name>
<pc_ip>10.10.10.10</pc_ip>
<pc_hwStatus>Working</pc_hwStatus>
</PC>
<PC>
<pc_name>esc02</pc_name>
<pc_ip>10.10.10.11</pc_ip>
<pc_hwStatus>Under Maintenance</pc_hwStatus>
</PC>
</PCs>";
}
}
}

Method .Element returns the first element with the specified name.
You can get the whole list with method .Elements, and iterate this list to find the one you are looking for.

How to modify DocumentElement.Prefix in XmlDocument

I have some sets of xml in which I have to add namespace prefix on nodes which doesn't have any prefix.
I have written a code which works for all nodes other than root element.
Please point me to the thing which I can do change the root element prefix as well.
private void ReplaceFile(string xmlfile)
{
XmlDocument doc = new XmlDocument();
doc.Load(xmlfile);
var a = doc.CreateAttribute("xmlns:mailxml12tm");
a.Value = "http://idealliance.org/Specs/mailxml12.0a/mailxml_tm";
doc.DocumentElement.Attributes.Append(a);
doc.DocumentElement.Prefix = "mailxml12tm";
//foreach (XmlNode item in doc.SelectNodes("//*").Cast<XmlNode>().Where(item => item.Prefix.Length == 0))
//{
// item.Prefix = "mailxml12tm";
//}
doc.Save(xmlfile);
}
The xml file:
<DeliveryApptCreateRequest
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
p3:ApptType="Pallet" p3:PickupOrDelivery="Delivery"
p3:ShipperApptRequestID="4490B0C07355" p3:SchedulerCRID="6498874"
xmlns:p3="http://idealliance.org/Specs/mailxml12.0a/mailxml_defs">
<SubmitterTrackingID xmlns="http://idealliance.org/Specs/mailxml12.0a/mailxml_tm">2CAD3FBC71B1E1517021</SubmitterTrackingID>
<DestinationEntry xmlns="http://idealliance.org/Specs/mailxml12.0a/mailxml_tm">No</DestinationEntry>
<OneTimeAppt xmlns="http://idealliance.org/Specs/mailxml12.0a/mailxml_tm">
<PreferredAppt>2012-07-01T09:00:00Z</PreferredAppt>
</OneTimeAppt>
</DeliveryApptCreateRequest>

Have you seen this answer: https://stackoverflow.com/a/2255337/219344
by Jeff Sternal?
If you've already declared your namespace in the root node, you just
need to change the SetAttribute call to use the unprefixed attribute
name. So if your root node defines a namespace like this:
<People xmlns:s='http://niem.gov/niem/structures/2.0'>
You can do this and the attribute will pick up the prefix you've
already established:
// no prefix on the first argument - it will be rendered as //
s:id='ID_Person_01' TempElement.SetAttribute("id",
"http://niem.gov/niem/structures/2.0", "ID_Person_01");
If you have not yet declared the namespace (and its prefix), the
three-string XmlDocument.CreateAttribute overload will do it for you:
// Adds the declaration to your root node var attribute =
xmlDocToRef.CreateAttribute("s", "id",
"http://niem.gov/niem/structures/2.0"); attribute.InnerText =
"ID_Person_01" TempElement.SetAttributeNode(attribute);

You can use the following:
XmlDocument doc = new XmlDocument();
doc.LoadXml("<test xmlns='123'/>");
XmlElement e = doc.DocumentElement;
e.Prefix = "a";
Console.WriteLine(doc.InnerXml);
Output:
<a:test xmlns="123" xmlns:a="123" />
Founded in msdn.
Edit:
Since it does not work with your main element you can use .Replace("<", "<Prefixe:")); on your root element as a String. It's not pretty but it does the job.

XPathSelectElements returns null

Load function is already defined in xmlData class
public class XmlData
{
public void Load(XElement xDoc)
{
var id = xDoc.XPathSelectElements("//ID");
var listIds = xDoc.XPathSelectElements("/Lists//List/ListIDS/ListIDS");
}
}
I'm just calling the Load function from my end.
XmlData aXmlData = new XmlData();
string input, stringXML = "";
TextReader aTextReader = new StreamReader("D:\\test.xml");
while ((input = aTextReader.ReadLine()) != null)
{
stringXML += input;
}
XElement Content = XElement.Parse(stringXML);
aXmlData.Load(Content);
in load function,im getting both id and and listIds as null.
My test.xml contains
<SEARCH>
<ID>11242</ID>
<Lists>
<List CURRENT="true" AGGREGATEDCHANGED="false">
<ListIDS>
<ListID>100567</ListID>
<ListID>100564</ListID>
<ListID>100025</ListID>
<ListID>2</ListID>
<ListID>1</ListID>
</ListIDS>
</List>
</Lists>
</SEARCH>

EDIT: Your sample XML doesn't have an id element in the namespace with the nss alias. It would be <nss:id> in that case, or there'd be a default namespace set up. I've assumed for this answer that in reality the element you're looking for is in the namespace.
Your query is trying to find an element called id at the root level. To find all id elements, you need:
var tempId = xDoc.XPathSelectElements("//nss:id", ns);
... although personally I'd use:
XDocument doc = XDocument.Parse(...);
XNamespace nss = "http://schemas.microsoft.com/SQLServer/reporting/reportdesigner";
// Or use FirstOrDefault(), or whatever...
XElement idElement = doc.Descendants(nss + "id").Single();
(I prefer using the query methods on LINQ to XML types instead of XPath... I find it easier to avoid silly syntax errors etc.)
Your sample code is also unclear as you're using xDoc which hasn't been declared... it helps to write complete examples, ideally including everything required to compile and run as a console app.

I am looking at the question 3 hours after it was submitted and 41 minutes after it was (last) edited.
There are no namespaces defined in the provided XML document.
var listIds = xDoc.XPathSelectElements("/Lists//List/ListIDS/ListIDS");
This XPath expression obviously doesn't select any node from the provided XML document, because the XML document doesn't have a top element named Lists (the name of the actual top element is SEARCH)
var id = xDoc.XPathSelectElements("//ID");
in load function,im getting both id and and listIds as null.
This statement is false, because //ID selects the only element named ID in the provided XML document, thus the value of the C# variable id is non-null. Probably you didn't test thoroughly after editing the XML document.
Most probably the original ID element belonged to some namespace. But now it is in "no namespace" and the XPath expression above does select it.

string xmldocument = "<response xmlns:nss=\"http://schemas.microsoft.com/SQLServer/reporting/reportdesigner\"><action>test</action><id>1</id></response>";
XElement Content = XElement.Parse(xmldocument);
XPathNavigator navigator = Content.CreateNavigator();
XmlNamespaceManager ns = new XmlNamespaceManager(navigator.NameTable);
ns.AddNamespace("nss", "http://schemas.microsoft.com/SQLServer/reporting/reportdesigner");
var tempId = navigator.SelectSingleNode("/id");

The reason for the null value or system returned value is due to the following
var id = xDoc.XPathSelectElements("//ID");
XpathSElectElements is System.xml.linq.XElment which is linq queried date. It cannot be directly outputed as such.
To Get individual first match element
use XPathSelectElement("//ID");
You can check the number of occurrences using XPathSelectElements as
var count=xDoc.XPathSelectElements("//ID").count();
you can also query the linq statement as order by using specific conditions
Inorder to get node value from a list u can use this
foreach (XmlNode xNode in xDoc.SelectNodes("//ListIDS/ListID"))
{
Console.WriteLine(xNode.InnerText);
}
For Second list you havnt got the value since, the XPath for list items is not correct

xmldoc.Childnodes.item() question

I decided to try out the tutorial on this website
http://www.csharphelp.com/2006/05/creating-a-xml-document-with-c/
Here's my code, which is more or less the same but a bit easier to read
using System;
using System.Xml;
public class Mainclass
{
public static void Main()
{
XmlDocument XmlDoc = new XmlDocument();
XmlDocument xmldoc;
XmlNode node1;
node1 = XmlDoc.CreateNode(XmlNodeType.XmlDeclaration, "", "");
XmlDoc.AppendChild(node1);
XmlElement element1;
element1 = XmlDoc.CreateElement("", "ROOT", "");
XmlText text1;
text1 = XmlDoc.CreateTextNode("this is the text of the root element");
element1.AppendChild(text1);
// appends the text specified above to the element1
XmlDoc.AppendChild(element1);
// another element
XmlElement element2;
element2 = XmlDoc.CreateElement("", "AnotherElement", "");
XmlText text2;
text2 = XmlDoc.CreateTextNode("This is the text of this element");
element2.AppendChild(text2);
XmlDoc.ChildNodes.Item(1).AppendChild(element2);
}
}
So far, I'm liking XmlDocument, but I can't figure out how this line works
XmlDoc.ChildNodes.Item(1).AppendChild(element2);
Specifically, the Item() part of it
according to MSDN...
//
// Summary:
// Retrieves a node at the given index.
//
// Parameters:
// index:
// Zero-based index into the list of nodes.
//
// Returns:
// The System.Xml.XmlNode in the collection. If index is greater than or equal
// to the number of nodes in the list, this returns null.
However, I'm still not really sure what "index" refers to, or what Item() does. Does it move down the tree or down a branch?
Also, when I was looking at it, I thought it would end up like this
what I thought would happen:
<?xml version="1.0"?>
<ROOT>this is the text of the root element</ROOT>
<AnotherElement>This is the text of this element</AnotherElement>
but it ended up like this
Actual output
<?xml version="1.0"?>
<ROOT>this is the text of the root element
<AnotherElement>This is the text of this element</AnotherElement>
</ROOT>
(formatting added)

The ChildNodes property returns the XmlNodeList of immediate children of what you call it on. Item then finds the nth member of that list. It won't recurse into grand-children etc. In particular, I believe in this case Item(0) would return the XML declaration, and Item(1) returns the root element. A nicer way of expressing "get to the root element" would be to use XmlDocument.DocumentElement.
Note that your "expected" output wouldn't even be valid XML - an XML document can only have one root element.
To be honest, this isn't a terribly nice use of it - and in particular I would recommend using LINQ to XML rather than XmlDocument if you possibly can. It's not particularly clear what you're trying to achieve with the code you've given, but it would almost certainly be much simpler in LINQ to XML.